Young men who have sex with men (YMSM) (aged 15-25) are less likely to know their HIV status than older MSM. HIV-positive YMSM are also less likely to be virally suppressed. The structural processes that place these youth at higher risk for HIV infection also increase their vulnerability for substance use, misuse, and abuse. These intertwining epidemics create feedback loops that negate the optimal delivery of HIV prevention and care services to substance-using YMSM. Given the limited and inconsistent focus placed on the HIV prevention and care service gaps faced by substance using) in the United States, Consistent with the current RFA's purpose to Seek, Test, Treat And Retain Youth And Young Adults Living With Or At High Risk For Acquiring HIV (RFA-DA-15-019), we propose to develop and evaluate an innovative service delivery model that integrates a substance use brief intervention (SUBI) within HIV standard of care (SOC) services in the three largest AIDS Service Organizations (ASO) serving high-risk YMSM in the Detroit Metro Area. The intervention comprises of two ASOs visits, at which time participants receive either SOC or SUBI from a trained HIV test counselor. At each intervention visit, 300 YMSM will receive SOC or SUBI. To examine how the sequencing of interventions impacts efficacy we proposed to randomize at baseline 600 ATOD-using high-risk YMSM aged 15-25 in the DMA into a 4-arm factorial randomized controlled trial (SOC-only, SOC+SUBI, SUBI+SOC, SUBI+SUBI). We will follow YMSM over a 15-month period, collecting both behavioral and biomarker (STIs, Substance Use) data every 3 months. Agency-level fidelity, acceptability and satisfaction, cost-effectiveness, and sustainability will also be evaluated and included in our analyses. Trial findings may offer a novel strategy to integrate substance use interventions into HIV standard of care and optimize the delivery of HIV services to substance- using YMSM.